title: Evidence that Bacillus subtilis sporulation induced by the stringent response is caused by the decrease in GTP or GDP.
abstract: Partial amino acid deprivation of Bacillus subtilis, which evokes the stringent response, initiates sporulation not because the highly phosphorylated guanine nucleotides guanosine-5'-diphosphate-3'-diphosphate (ppGpp) and guanosine-5'-triphosphate-3'-diphosphate (pppGpp) increase but because GTP decreases. This was shown with a mutant (Myc) partially resistant to mycophenolate, an inhibitor of IMP dehydrogenase. Upon amino acid deprivation, the Myc mutant (62032) showed the usual increase in ppGpp and pppGpp but a reduced decrease in GTP, and only few cells sporulated. Extensive sporulation was restored by the addition of mycophenolate or decoyinine, and inhibitor of GMP synthetase, which caused a further decrease in GTP.
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D001412:Bacillus subtilis / Q000235:genetics / Q000502:physiology*; D006150:Guanine Nucleotides / Q000378:metabolism*; D006153:Guanosine Diphosphate / Q000378:metabolism*; D006158:Guanosine Pentaphosphate / Q000378:metabolism; D006159:Guanosine Tetraphosphate / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism*; D009154:Mutation; D009173:Mycophenolic Acid / Q000494:pharmacology; D013171:Spores, Bacterial / Q000502:physiology
chemical_list: D000596:Amino Acids; D006150:Guanine Nucleotides; D006153:Guanosine Diphosphate; D006159:Guanosine Tetraphosphate; D006158:Guanosine Pentaphosphate; D006160:Guanosine Triphosphate; D009173:Mycophenolic Acid